Such devices for grouping and/or separating are used in the inlet area of packaging machines that insert beverage containers or bottles into cartons or bottle crates. Quadrangular containers for beverage containers or bottles are usually fed in a closed row without any gaps in between. The plane-parallel side surfaces of the quadrangular containers pointing in the conveying direction and in the direction opposite to the conveying direction contact each other directly. The containers supplied to the packaging machine have to be adjusted to defined distances separately or group wise. This is independent of the working model of the packaging machine, i.e. if the packaging machine works tact wise or continuously.
For this reason separating rollers, plungers or the like are used that are introducible into the conveying system from below in a controlled fashion. The separating rollers, plungers or the like become engaged with the lower part of the container and raise it to a certain level above the conveyor plane. Leading containers are accelerated and/or trailing containers are slowed down by engaging either the backside of the leading container or the front side of the trailing container. In this way a separation or a grouping of the containers is possible by enlarging the distances between them. A gap between the containers is created in an initially continuous row. Further one the separating rollers or plungers will be taken out of the conveying device by a downward movement into a position in which they are not engaged with the containers anymore. These known separation or grouping mechanisms lead to a disturbance in the container inlet and also tend to bring about a significant noise development. Furthermore the containers are subject to great mechanical stress which can lead to unwanted damages.
Devices for separation or grouping of quadrangular packages where the articles are lifted perpendicular to the conveying plane are known from DE 21 43 910 C2, DE 25 40 985 A1, DE 2850456 A1, DE 31 44 449 A1, DE 39 38 548 A1, DE 41 14 475 A1 and DE 10 2004 042 474 A1.
DE 298 07 979 U1 furthermore depicts a device for grouping or separating of articles where the articles are transported in one or more closed rows on a conveyor belt and are pulled apart individually or group wise Hereby two elements can be moved forward and backward parallel to the transport direction independently of each other. These two elements are engaged or disengaged with the articles in a controlled fashion. During a forward movement in transport direction the elements take up a working position whereby the elements interfere with the transport path of the articles. The elements are movable into a ready position by a backward movement in the same transport path against the transport direction, whereby a space between the elements in ready position and the articles is created. If the incoming articles transported in several rows, then two individually movable elements are assigned to each conveying path.
From DE 603 00 115 T2 a device for separating, isolating or grouping of continuously fed products or bottles is known that has a feeding conveyor belt and separating devices for the grouping of the bottles.
EP 1 247 769 A1 describes a further device for grouping bottles or other articles that are transported on a horizontal conveyor belt. Separating fingers are arranged on an endlessly circumferential track that is located below the transport plane. The separating fingers immerse between the bottles from below. Therefore the movement of the bottles compared to the movement of the conveyor belt is slowed down during the horizontal movement of the bottles in transport direction resulting in the formation of gaps. The arrangement or the distance between a plurality of separating fingers determines the required groups of two, three or more bottles that are slowed down compared to the other bottles. The separating fingers are arranged pair wise and each engage with the lower part of the outer surface of the bottles within each transport lane.
By each of the known grouping devices using separating elements or fingers emerging from below a transport lane, the exact positioning of the fingers between the bottles to be separated is very important. Even if the positioning is very exact it often happens that the bottles to be separated are displaced slightly during the engagement with the fingers. This leads to disturbances of the precise processes. But the separating fingers need to have a certain thickness. Otherwise it might happen that some bottles just pass the separating fingers that vertically block the path.